Allylic halides allylations, allyltrimethylsilane

Allyltrimethylsilanes. Trimethylsilyllithium reacts with primary (E)-allylic halides to form the corresponding allyltrimethylsilanes. Reaction of the reagent prepared from (CH,),SiLi and Cul in HMPT with these halides results in the isomeric 3-trimethylsilyl-1-alkene. ... 

Guindon investigated diastereoselective allylation reactions of alkyl halides and phenyl selenides using allylsilanes [68], For example, substrate 116 is allylated by allyltrimethylsilane in the presence of magnesium bromide diethyl etherate using triethylboranc as an initiator (Scheme 25). No tin is required in these reactions. 

Reaction with Allylic Halides, Alcohols, and their Derivatives. Allylation of allyl and propargyl trimethylsilyl ethers as well as benzyl and propargylic alcohol derivatives proceeds in the presence of a catalytic amount of Lewis acids, such as ZnC, TMS(OTf), and B(C6F5)3. Direct substitutions of the hydroxyl group of allylic, ben-zylic, and propargylic alcohols are catalyzed by HN(S02F)2, a rhenium-oxo complex, and InCls (eq 27). A combination of chlorodimethylsilane and allyltrimethylsilane effectively promotes the deoxygenative allylation of aromatic ketones in the presence of a catalytic amount of an indium compound, such as indium trihalide or metallic indium (eq 28). Allylation of cyclic allylic acetates with allyltrimethylsilane can be catalyzed by molecular iodine. ... 

Recently, Co(III)-allyl complexes have been described to be sulfonylated regiospecifi-cally by sulfonyl halides under irradiation232 (equation 42). Similarly, allyl methyl sulfone has been obtained from allyltrimethylsilane under copper(I) catalysis213. 

Silver(I) compounds are often used as promoters for substitution reactions of aliphatic halides with carbon nucleophiles. A cyclic (8-bromo ether 29 can be reacted with allyltrimethylsilane (30) imder the influence of AgBp4, yielding a mixture of ally-lated products 31 and 32 (Sch. 7) [15]. Product 31 is formed by direct substitution of the bromine atom in ether 29 by an allyl group and isomeric ether 32 arises from the carboxonium ion which is generated by debromination and subsequent [l,2]-hydrogen shift. A synthesis of optically active 4-allylazetidinone 33 (Ft = phthalimido) has also been achieved by employing the silver-promoted substitution reaction of 4-chloro-azetidinone 34 with allylsilane 30 [16]... 

In the presence of excess acetyl halide and a tin(II) catalyst aromatic acetals react with allyltrimethylsilane to give a-allylbenzyl halides in good yield by double substitution of the acetal alkoxy groups (Scheme 10.127) [365]. The indium-catalyzed tandem reaction using a hydrosilane-allylsilane system enables deoxygenative allylation of aromatic ketones [366]. 

As a Carbon Nucleophile in Lewis Base-catalyzed Reactions. Allylation of alkyl iodides with allyltrimethylsilane proceeds in the presence of phosphazenium fluoride. Tetra-butylammonium triphenyldifluorosilicate (TBAT) is useful for allylation of aldehydes, ketones, imines, and alkyl halides with allyltrimethylsilane (eq 63). 55 Similarly, TBAHF2 is an effective catalyst for allylation of aldehydes. The homoallylamines are synthesized from allyltrimethylsilane and imines with a catalytic amount of TBAF (eq 64). The reactions of thioketones as well as sulfines with allyltrimethylsilane can be mediated by TBAF to give allylic sulfides and allyl sulfoxides, respectively. Besides fluoride ion, 2,8,9-triisopropyl-2,5,8,9-tetra-aza-1-phosphabi-cyclo[3.3.3]undecane promotes the allylation of aldehydes with allyltrimethylsilane as a Lewis base catalyst (eq 65). ... 

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